// SPDX-License-Identifier: GPL-2.0
/*
 * Silicon Laboratories CP210x USB to RS232 serial adaptor driver
 *
 * Copyright (C) 2005 Craig Shelley (craig@microtron.org.uk)
 *
 * Support to set flow control line levels using TIOCMGET and TIOCMSET
 * thanks to Karl Hiramoto karl@hiramoto.org.  RTSCTS hardware flow
 * control thanks to Munir Nassar nassarmu@real-time.com
 *
 */

#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/slab.h>
#include <linux/tty.h>
#include <linux/tty_flip.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/usb.h>
#include <linux/uaccess.h>
#include <linux/usb/serial.h>

#define DRIVER_DESC "Silicon Labs CP210x RS232 serial adaptor driver"

/*
 * Function Prototypes
 */
static int cp210x_open(struct tty_struct *tty, struct usb_serial_port *);
static void cp210x_close(struct usb_serial_port *);
static void cp210x_get_termios(struct tty_struct *, struct usb_serial_port *);
static void cp210x_get_termios_port(struct usb_serial_port *port,
    tcflag_t *cflagp, unsigned int *baudp);
static void cp210x_change_speed(struct tty_struct *, struct usb_serial_port *,
    struct ktermios *);
static void cp210x_set_termios(struct tty_struct *, struct usb_serial_port *,
    struct ktermios*);
static bool cp210x_tx_empty(struct usb_serial_port *port);
static int cp210x_tiocmget(struct tty_struct *);
static int cp210x_tiocmset(struct tty_struct *, unsigned int, unsigned int);
static int cp210x_tiocmset_port(struct usb_serial_port *port,
    unsigned int, unsigned int);
static void cp210x_break_ctl(struct tty_struct *, int);
static int cp210x_startup(struct usb_serial *);
static void cp210x_release(struct usb_serial *);
static void cp210x_dtr_rts(struct usb_serial_port *p, int on);
static void cp210x_process_read_urb(struct urb * urb);
static int cp210x_ioctl(struct tty_struct *tty, unsigned int cmd,
    unsigned long arg);

static const struct usb_device_id id_table[] = {
    { USB_DEVICE(0x045B, 0x0053) }, /* Renesas RX610 RX-Stick */
    { USB_DEVICE(0x0471, 0x066A) }, /* AKTAKOM ACE-1001 cable */
    { USB_DEVICE(0x0489, 0xE000) }, /* Pirelli Broadband S.p.A, DP-L10 SIP/GSM Mobile */
    { USB_DEVICE(0x0489, 0xE003) }, /* Pirelli Broadband S.p.A, DP-L10 SIP/GSM Mobile */
    { USB_DEVICE(0x0745, 0x1000) }, /* CipherLab USB CCD Barcode Scanner 1000 */
    { USB_DEVICE(0x0846, 0x1100) }, /* NetGear Managed Switch M4100 series, M5300 series, M7100 series */
    { USB_DEVICE(0x08e6, 0x5501) }, /* Gemalto Prox-PU/CU contactless smartcard reader */
    { USB_DEVICE(0x08FD, 0x000A) }, /* Digianswer A/S , ZigBee/802.15.4 MAC Device */
    { USB_DEVICE(0x0908, 0x01FF) }, /* Siemens RUGGEDCOM USB Serial Console */
	{ USB_DEVICE(0x0B00, 0x3070) }, /* Ingenico 3070 */
    { USB_DEVICE(0x0BED, 0x1100) }, /* MEI (TM) Cashflow-SC Bill/Voucher Acceptor */
    { USB_DEVICE(0x0BED, 0x1101) }, /* MEI series 2000 Combo Acceptor */
    { USB_DEVICE(0x0FCF, 0x1003) }, /* Dynastream ANT development board */
    { USB_DEVICE(0x0FCF, 0x1004) }, /* Dynastream ANT2USB */
    { USB_DEVICE(0x0FCF, 0x1006) }, /* Dynastream ANT development board */
    { USB_DEVICE(0x0FDE, 0xCA05) }, /* OWL Wireless Electricity Monitor CM-160 */
    { USB_DEVICE(0x10A6, 0xAA26) }, /* Knock-off DCU-11 cable */
    { USB_DEVICE(0x10AB, 0x10C5) }, /* Siemens MC60 Cable */
    { USB_DEVICE(0x10B5, 0xAC70) }, /* Nokia CA-42 USB */
    { USB_DEVICE(0x10C4, 0x0F91) }, /* Vstabi */
    { USB_DEVICE(0x10C4, 0x1101) }, /* Arkham Technology DS101 Bus Monitor */
    { USB_DEVICE(0x10C4, 0x1601) }, /* Arkham Technology DS101 Adapter */
    { USB_DEVICE(0x10C4, 0x800A) }, /* SPORTident BSM7-D-USB main station */
    { USB_DEVICE(0x10C4, 0x803B) }, /* Pololu USB-serial converter */
    { USB_DEVICE(0x10C4, 0x8044) }, /* Cygnal Debug Adapter */
    { USB_DEVICE(0x10C4, 0x804E) }, /* Software Bisque Paramount ME build-in converter */
    { USB_DEVICE(0x10C4, 0x8053) }, /* Enfora EDG1228 */
    { USB_DEVICE(0x10C4, 0x8054) }, /* Enfora GSM2228 */
	{ USB_DEVICE(0x10C4, 0x8056) }, /* Lorenz Messtechnik devices */
    { USB_DEVICE(0x10C4, 0x8066) }, /* Argussoft In-System Programmer */
    { USB_DEVICE(0x10C4, 0x806F) }, /* IMS USB to RS422 Converter Cable */
    { USB_DEVICE(0x10C4, 0x807A) }, /* Crumb128 board */
    { USB_DEVICE(0x10C4, 0x80C4) }, /* Cygnal Integrated Products, Inc., Optris infrared thermometer */
    { USB_DEVICE(0x10C4, 0x80CA) }, /* Degree Controls Inc */
    { USB_DEVICE(0x10C4, 0x80DD) }, /* Tracient RFID */
    { USB_DEVICE(0x10C4, 0x80F6) }, /* Suunto sports instrument */
    { USB_DEVICE(0x10C4, 0x8115) }, /* Arygon NFC/Mifare Reader */
    { USB_DEVICE(0x10C4, 0x813D) }, /* Burnside Telecom Deskmobile */
    { USB_DEVICE(0x10C4, 0x813F) }, /* Tams Master Easy Control */
    { USB_DEVICE(0x10C4, 0x814A) }, /* West Mountain Radio RIGblaster P&P */
    { USB_DEVICE(0x10C4, 0x814B) }, /* West Mountain Radio RIGtalk */
    { USB_DEVICE(0x2405, 0x0003) }, /* West Mountain Radio RIGblaster Advantage */
    { USB_DEVICE(0x10C4, 0x8156) }, /* B&G H3000 link cable */
    { USB_DEVICE(0x10C4, 0x815E) }, /* Helicomm IP-Link 1220-DVM */
    { USB_DEVICE(0x10C4, 0x815F) }, /* Timewave HamLinkUSB */
    { USB_DEVICE(0x10C4, 0x817C) }, /* CESINEL MEDCAL N Power Quality Monitor */
    { USB_DEVICE(0x10C4, 0x817D) }, /* CESINEL MEDCAL NT Power Quality Monitor */
    { USB_DEVICE(0x10C4, 0x817E) }, /* CESINEL MEDCAL S Power Quality Monitor */
    { USB_DEVICE(0x10C4, 0x818B) }, /* AVIT Research USB to TTL */
    { USB_DEVICE(0x10C4, 0x819F) }, /* MJS USB Toslink Switcher */
    { USB_DEVICE(0x10C4, 0x81A6) }, /* ThinkOptics WavIt */
    { USB_DEVICE(0x10C4, 0x81A9) }, /* Multiplex RC Interface */
    { USB_DEVICE(0x10C4, 0x81AC) }, /* MSD Dash Hawk */
    { USB_DEVICE(0x10C4, 0x81AD) }, /* INSYS USB Modem */
    { USB_DEVICE(0x10C4, 0x81C8) }, /* Lipowsky Industrie Elektronik GmbH, Baby-JTAG */
    { USB_DEVICE(0x10C4, 0x81D7) }, /* IAI Corp. RCB-CV-USB USB to RS485 Adaptor */
    { USB_DEVICE(0x10C4, 0x81E2) }, /* Lipowsky Industrie Elektronik GmbH, Baby-LIN */
    { USB_DEVICE(0x10C4, 0x81E7) }, /* Aerocomm Radio */
    { USB_DEVICE(0x10C4, 0x81E8) }, /* Zephyr Bioharness */
    { USB_DEVICE(0x10C4, 0x81F2) }, /* C1007 HF band RFID controller */
    { USB_DEVICE(0x10C4, 0x8218) }, /* Lipowsky Industrie Elektronik GmbH, HARP-1 */
    { USB_DEVICE(0x10C4, 0x822B) }, /* Modem EDGE(GSM) Comander 2 */
    { USB_DEVICE(0x10C4, 0x826B) }, /* Cygnal Integrated Products, Inc., Fasttrax GPS demonstration module */
    { USB_DEVICE(0x10C4, 0x8281) }, /* Nanotec Plug & Drive */
    { USB_DEVICE(0x10C4, 0x8293) }, /* Telegesis ETRX2USB */
    { USB_DEVICE(0x10C4, 0x82EF) }, /* CESINEL FALCO 6105 AC Power Supply */
    { USB_DEVICE(0x10C4, 0x82F1) }, /* CESINEL MEDCAL EFD Earth Fault Detector */
    { USB_DEVICE(0x10C4, 0x82F2) }, /* CESINEL MEDCAL ST Network Analyzer */
    { USB_DEVICE(0x10C4, 0x82F4) }, /* Starizona MicroTouch */
    { USB_DEVICE(0x10C4, 0x82F9) }, /* Procyon AVS */
    { USB_DEVICE(0x10C4, 0x8341) }, /* Siemens MC35PU GPRS Modem */
    { USB_DEVICE(0x10C4, 0x8382) }, /* Cygnal Integrated Products, Inc. */
    { USB_DEVICE(0x10C4, 0x83A8) }, /* Amber Wireless AMB2560 */
	{ USB_DEVICE(0x10C4, 0x83AA) }, /* Mark-10 Digital Force Gauge */
    { USB_DEVICE(0x10C4, 0x83D8) }, /* DekTec DTA Plus VHF/UHF Booster/Attenuator */
    { USB_DEVICE(0x10C4, 0x8411) }, /* Kyocera GPS Module */
    { USB_DEVICE(0x10C4, 0x8418) }, /* IRZ Automation Teleport SG-10 GSM/GPRS Modem */
    { USB_DEVICE(0x10C4, 0x846E) }, /* BEI USB Sensor Interface (VCP) */
    { USB_DEVICE(0x10C4, 0x8470) }, /* Juniper Networks BX Series System Console */
    { USB_DEVICE(0x10C4, 0x8477) }, /* Balluff RFID */
    { USB_DEVICE(0x10C4, 0x84B6) }, /* Starizona Hyperion */
    { USB_DEVICE(0x10C4, 0x851E) }, /* CESINEL MEDCAL PT Network Analyzer */
    { USB_DEVICE(0x10C4, 0x85A7) }, /* LifeScan OneTouch Verio IQ */
    { USB_DEVICE(0x10C4, 0x85B8) }, /* CESINEL ReCon T Energy Logger */
    { USB_DEVICE(0x10C4, 0x85EA) }, /* AC-Services IBUS-IF */
    { USB_DEVICE(0x10C4, 0x85EB) }, /* AC-Services CIS-IBUS */
    { USB_DEVICE(0x10C4, 0x85F8) }, /* Virtenio Preon32 */
    { USB_DEVICE(0x10C4, 0x8664) }, /* AC-Services CAN-IF */
    { USB_DEVICE(0x10C4, 0x8665) }, /* AC-Services OBD-IF */
    { USB_DEVICE(0x10C4, 0x8856) },    /* CEL EM357 ZigBee USB Stick - LR */
    { USB_DEVICE(0x10C4, 0x8857) },    /* CEL EM357 ZigBee USB Stick */
    { USB_DEVICE(0x10C4, 0x88A4) }, /* MMB Networks ZigBee USB Device */
    { USB_DEVICE(0x10C4, 0x88A5) }, /* Planet Innovation Ingeni ZigBee USB Device */
    { USB_DEVICE(0x10C4, 0x88FB) }, /* CESINEL MEDCAL STII Network Analyzer */
    { USB_DEVICE(0x10C4, 0x8938) }, /* CESINEL MEDCAL S II Network Analyzer */
    { USB_DEVICE(0x10C4, 0x8946) }, /* Ketra N1 Wireless Interface */
    { USB_DEVICE(0x10C4, 0x8962) }, /* Brim Brothers charging dock */
    { USB_DEVICE(0x10C4, 0x8977) },    /* CEL MeshWorks DevKit Device */
    { USB_DEVICE(0x10C4, 0x8998) }, /* KCF Technologies PRN */
    { USB_DEVICE(0x10C4, 0x89A4) }, /* CESINEL FTBC Flexible Thyristor Bridge Controller */
    { USB_DEVICE(0x10C4, 0x89FB) }, /* Qivicon ZigBee USB Radio Stick */
    { USB_DEVICE(0x10C4, 0x8A2A) }, /* HubZ dual ZigBee and Z-Wave dongle */
    { USB_DEVICE(0x10C4, 0x8A5E) }, /* CEL EM3588 ZigBee USB Stick Long Range */
    { USB_DEVICE(0x10C4, 0x8B34) }, /* Qivicon ZigBee USB Radio Stick */
    { USB_DEVICE(0x10C4, 0xEA60) }, /* Silicon Labs factory default */
    { USB_DEVICE(0x10C4, 0xEA61) }, /* Silicon Labs factory default */
    { USB_DEVICE(0x10C4, 0xEA63) }, /* Silicon Labs Windows Update (CP2101-4/CP2102N) */
    { USB_DEVICE(0x10C4, 0xEA70) }, /* Silicon Labs factory default */
    { USB_DEVICE(0x10C4, 0xEA80) }, /* Silicon Labs factory default */
    { USB_DEVICE(0x10C4, 0xEA71) }, /* Infinity GPS-MIC-1 Radio Monophone */
    { USB_DEVICE(0x10C4, 0xEA7A) }, /* Silicon Labs Windows Update (CP2105) */
    { USB_DEVICE(0x10C4, 0xEA7B) }, /* Silicon Labs Windows Update (CP2108) */
    { USB_DEVICE(0x10C4, 0xF001) }, /* Elan Digital Systems USBscope50 */
    { USB_DEVICE(0x10C4, 0xF002) }, /* Elan Digital Systems USBwave12 */
    { USB_DEVICE(0x10C4, 0xF003) }, /* Elan Digital Systems USBpulse100 */
    { USB_DEVICE(0x10C4, 0xF004) }, /* Elan Digital Systems USBcount50 */
    { USB_DEVICE(0x10C5, 0xEA61) }, /* Silicon Labs MobiData GPRS USB Modem */
    { USB_DEVICE(0x10CE, 0xEA6A) }, /* Silicon Labs MobiData GPRS USB Modem 100EU */
    { USB_DEVICE(0x12B8, 0xEC60) }, /* Link G4 ECU */
    { USB_DEVICE(0x12B8, 0xEC62) }, /* Link G4+ ECU */
    { USB_DEVICE(0x13AD, 0x9999) }, /* Baltech card reader */
    { USB_DEVICE(0x1555, 0x0004) }, /* Owen AC4 USB-RS485 Converter */
    { USB_DEVICE(0x155A, 0x1005) },    /* ELDAT Easywave RX09 dongle */
    { USB_DEVICE(0x155A, 0x1006) },    /* ELDAT Easywave RX09 dongle */
    { USB_DEVICE(0x166A, 0x0201) }, /* Clipsal 5500PACA C-Bus Pascal Automation Controller */
    { USB_DEVICE(0x166A, 0x0301) }, /* Clipsal 5800PC C-Bus Wireless PC Interface */
    { USB_DEVICE(0x166A, 0x0303) }, /* Clipsal 5500PCU C-Bus USB interface */
    { USB_DEVICE(0x166A, 0x0304) }, /* Clipsal 5000CT2 C-Bus Black and White Touchscreen */
    { USB_DEVICE(0x166A, 0x0305) }, /* Clipsal C-5000CT2 C-Bus Spectrum Colour Touchscreen */
    { USB_DEVICE(0x166A, 0x0401) }, /* Clipsal L51xx C-Bus Architectural Dimmer */
    { USB_DEVICE(0x166A, 0x0101) }, /* Clipsal 5560884 C-Bus Multi-room Audio Matrix Switcher */
    { USB_DEVICE(0x16C0, 0x09B0) }, /* Lunatico Seletek */
    { USB_DEVICE(0x16C0, 0x09B1) }, /* Lunatico Seletek */
    { USB_DEVICE(0x16D6, 0x0001) }, /* Jablotron serial interface */
    { USB_DEVICE(0x16DC, 0x0010) }, /* W-IE-NE-R Plein & Baus GmbH PL512 Power Supply */
    { USB_DEVICE(0x16DC, 0x0011) }, /* W-IE-NE-R Plein & Baus GmbH RCM Remote Control for MARATON Power Supply */
    { USB_DEVICE(0x16DC, 0x0012) }, /* W-IE-NE-R Plein & Baus GmbH MPOD Multi Channel Power Supply */
    { USB_DEVICE(0x16DC, 0x0015) }, /* W-IE-NE-R Plein & Baus GmbH CML Control, Monitoring and Data Logger */
    { USB_DEVICE(0x17A8, 0x0001) }, /* Kamstrup Optical Eye/3-wire */
    { USB_DEVICE(0x17A8, 0x0005) }, /* Kamstrup M-Bus Master MultiPort 250D */
    { USB_DEVICE(0x17F4, 0xAAAA) }, /* Wavesense Jazz blood glucose meter */
    { USB_DEVICE(0x1843, 0x0200) }, /* Vaisala USB Instrument Cable */
    { USB_DEVICE(0x18EF, 0xE00F) }, /* ELV USB-I2C-Interface */
    { USB_DEVICE(0x18EF, 0xE025) }, /* ELV Marble Sound Board 1 */
    { USB_DEVICE(0x18EF, 0xE030) }, /* ELV ALC 8xxx Battery Charger */
    { USB_DEVICE(0x18EF, 0xE032) }, /* ELV TFD500 Data Logger */
    { USB_DEVICE(0x1901, 0x0190) }, /* GE B850 CP2105 Recorder interface */
    { USB_DEVICE(0x1901, 0x0193) }, /* GE B650 CP2104 PMC interface */
    { USB_DEVICE(0x1901, 0x0194) },    /* GE Healthcare Remote Alarm Box */
    { USB_DEVICE(0x1901, 0x0195) },    /* GE B850/B650/B450 CP2104 DP UART interface */
    { USB_DEVICE(0x1901, 0x0196) },    /* GE B850 CP2105 DP UART interface */
    { USB_DEVICE(0x19CF, 0x3000) }, /* Parrot NMEA GPS Flight Recorder */
    { USB_DEVICE(0x1ADB, 0x0001) }, /* Schweitzer Engineering C662 Cable */
    { USB_DEVICE(0x1B1C, 0x1C00) }, /* Corsair USB Dongle */
    { USB_DEVICE(0x1BA4, 0x0002) },    /* Silicon Labs 358x factory default */
    { USB_DEVICE(0x1BE3, 0x07A6) }, /* WAGO 750-923 USB Service Cable */
    { USB_DEVICE(0x1D6F, 0x0010) }, /* Seluxit ApS RF Dongle */
    { USB_DEVICE(0x1E29, 0x0102) }, /* Festo CPX-USB */
    { USB_DEVICE(0x1E29, 0x0501) }, /* Festo CMSP */
    { USB_DEVICE(0x1FB9, 0x0100) }, /* Lake Shore Model 121 Current Source */
    { USB_DEVICE(0x1FB9, 0x0200) }, /* Lake Shore Model 218A Temperature Monitor */
    { USB_DEVICE(0x1FB9, 0x0201) }, /* Lake Shore Model 219 Temperature Monitor */
    { USB_DEVICE(0x1FB9, 0x0202) }, /* Lake Shore Model 233 Temperature Transmitter */
    { USB_DEVICE(0x1FB9, 0x0203) }, /* Lake Shore Model 235 Temperature Transmitter */
    { USB_DEVICE(0x1FB9, 0x0300) }, /* Lake Shore Model 335 Temperature Controller */
    { USB_DEVICE(0x1FB9, 0x0301) }, /* Lake Shore Model 336 Temperature Controller */
    { USB_DEVICE(0x1FB9, 0x0302) }, /* Lake Shore Model 350 Temperature Controller */
    { USB_DEVICE(0x1FB9, 0x0303) }, /* Lake Shore Model 371 AC Bridge */
    { USB_DEVICE(0x1FB9, 0x0400) }, /* Lake Shore Model 411 Handheld Gaussmeter */
    { USB_DEVICE(0x1FB9, 0x0401) }, /* Lake Shore Model 425 Gaussmeter */
    { USB_DEVICE(0x1FB9, 0x0402) }, /* Lake Shore Model 455A Gaussmeter */
    { USB_DEVICE(0x1FB9, 0x0403) }, /* Lake Shore Model 475A Gaussmeter */
    { USB_DEVICE(0x1FB9, 0x0404) }, /* Lake Shore Model 465 Three Axis Gaussmeter */
    { USB_DEVICE(0x1FB9, 0x0600) }, /* Lake Shore Model 625A Superconducting MPS */
    { USB_DEVICE(0x1FB9, 0x0601) }, /* Lake Shore Model 642A Magnet Power Supply */
    { USB_DEVICE(0x1FB9, 0x0602) }, /* Lake Shore Model 648 Magnet Power Supply */
    { USB_DEVICE(0x1FB9, 0x0700) }, /* Lake Shore Model 737 VSM Controller */
    { USB_DEVICE(0x1FB9, 0x0701) }, /* Lake Shore Model 776 Hall Matrix */
    { USB_DEVICE(0x2626, 0xEA60) }, /* Aruba Networks 7xxx USB Serial Console */
    { USB_DEVICE(0x3195, 0xF190) }, /* Link Instruments MSO-19 */
    { USB_DEVICE(0x3195, 0xF280) }, /* Link Instruments MSO-28 */
    { USB_DEVICE(0x3195, 0xF281) }, /* Link Instruments MSO-28 */
    { USB_DEVICE(0x3923, 0x7A0B) }, /* National Instruments USB Serial Console */
    { USB_DEVICE(0x413C, 0x9500) }, /* DW700 GPS USB interface */
    { } /* Terminating Entry */
};

MODULE_DEVICE_TABLE(usb, id_table);

struct cp210x_port_private {
    u8 bPartNumber;
    u8 bInterfaceNumber;
    bool has_swapped_line_ctl;

    int baud_bas;
    int custom_divisor;
    int flags;
    char prev_status;
    char transmit_empty;
    unsigned short max_packet_size;
    struct mutex lock;
};

static struct usb_serial_driver cp210x_device = {
    .driver = {
        .owner =        THIS_MODULE,
        .name =         "cp210x",
    },
    .id_table =         id_table,
    .num_ports =        1,
    .bulk_in_size =     256,
    .bulk_out_size =    256,
    .open =             cp210x_open,
    .close =            cp210x_close,
    .ioctl =            cp210x_ioctl,
    .break_ctl =        cp210x_break_ctl,
    .set_termios =      cp210x_set_termios,
    .tx_empty =         cp210x_tx_empty,
    .tiocmget =         cp210x_tiocmget,
    .tiocmset =         cp210x_tiocmset,
    .tiocmiwait =       usb_serial_generic_tiocmiwait,
    .get_icount =       usb_serial_generic_get_icount,
    .process_read_urb = cp210x_process_read_urb,
    // .process_read_urb = usb_serial_generic_read_bulk_callback,
    .attach  =          cp210x_startup,
    .release =          cp210x_release,
    .dtr_rts =          cp210x_dtr_rts
};

/* IOCTLs */
#define IOCTL_GPIOGET 0x8000
#define IOCTL_GPIOSET 0x8001

static struct usb_serial_driver * const serial_drivers[] = {
    &cp210x_device, NULL
};

/* Config request types */
#define REQTYPE_HOST_TO_INTERFACE 0x41
#define REQTYPE_INTERFACE_TO_HOST 0xC1
#define REQTYPE_HOST_TO_DEVICE    0x40
#define REQTYPE_DEVICE_TO_HOST    0xC0

/* Config request codes */
#define CP210X_IFC_ENABLE      0x00
#define CP210X_SET_BAUDDIV     0x01
#define CP210X_GET_BAUDDIV     0x02
#define CP210X_SET_LINE_CTL    0x03
#define CP210X_GET_LINE_CTL    0x04
#define CP210X_SET_BREAK       0x05
#define CP210X_IMM_CHAR        0x06
#define CP210X_SET_MHS         0x07
#define CP210X_GET_MDMSTS      0x08
#define CP210X_SET_XON         0x09
#define CP210X_SET_XOFF        0x0A
#define CP210X_SET_EVENTMASK   0x0B
#define CP210X_GET_EVENTMASK   0x0C
#define CP210X_SET_CHAR        0x0D
#define CP210X_GET_CHARS       0x0E
#define CP210X_GET_PROPS       0x0F
#define CP210X_GET_COMM_STATUS 0x10
#define CP210X_RESET           0x11
#define CP210X_PURGE           0x12
#define CP210X_SET_FLOW        0x13
#define CP210X_GET_FLOW        0x14
#define CP210X_EMBED_EVENTS    0x15
#define CP210X_GET_EVENTSTATE  0x16
#define CP210X_SET_CHARS       0x19
#define CP210X_GET_BAUDRATE    0x1D
#define CP210X_SET_BAUDRATE    0x1E
#define CP210X_VENDOR_SPECIFIC 0xFF

/* CP210X_IFC_ENABLE */
#define UART_ENABLE  0x0001
#define UART_DISABLE 0x0000

/* CP210X_(SET|GET)_BAUDDIV */
#define BAUD_RATE_GEN_FREQ 0x384000

/* CP210X_(SET|GET)_LINE_CTL */
#define BITS_DATA_MASK 0x0F00
#define BITS_DATA_5    0x0500
#define BITS_DATA_6    0x0600
#define BITS_DATA_7    0x0700
#define BITS_DATA_8    0x0800
#define BITS_DATA_9    0x0900

#define BITS_PARITY_MASK  0x00F0
#define BITS_PARITY_NONE  0x0000
#define BITS_PARITY_ODD   0x0010
#define BITS_PARITY_EVEN  0x0020
#define BITS_PARITY_MARK  0x0030
#define BITS_PARITY_SPACE 0x0040

#define BITS_STOP_MASK 0x000F
#define BITS_STOP_1    0x0000
#define BITS_STOP_1_5  0x0001
#define BITS_STOP_2    0x0002

/* CP210X_SET_BREAK */
#define BREAK_ON  0x0001
#define BREAK_OFF 0x0000

/* CP210X_(SET_MHS|GET_MDMSTS) */
#define CONTROL_DTR       0x0001
#define CONTROL_RTS       0x0002
#define CONTROL_CTS       0x0010
#define CONTROL_DSR       0x0020
#define CONTROL_RING      0x0040
#define CONTROL_DCD       0x0080
#define CONTROL_WRITE_DTR 0x0100
#define CONTROL_WRITE_RTS 0x0200

#define CP210X_STATUS_B0_MASK (CONTROL_CTS | CONTROL_DSR | CONTROL_RING | CONTROL_DCD)
#define CP210X_ESCAPE         0x1E
#define CP210X_DCD_CHANGE_BIT 0x08

/* CP210X_VENDOR_SPECIFIC values */
#define CP210X_READ_2NCONFIG	0x000E
#define CP210X_READ_LATCH  0x00C2
#define CP210X_GET_PARTNUM 0x370B
#define CP210X_GET_PORTCONFIG	0x370C
#define CP210X_GET_DEVICEMODE	0x3711
#define CP210X_WRITE_LATCH 0x37E1

/* Part number definitions */
#define CP210X_PARTNUM_CP2101 0x01
#define CP210X_PARTNUM_CP2102 0x02
#define CP210X_PARTNUM_CP2103 0x03
#define CP210X_PARTNUM_CP2104 0x04
#define CP210X_PARTNUM_CP2105 0x05
#define CP210X_PARTNUM_CP2108 0x08
#define CP210X_PARTNUM_CP2102N_QFN28	0x20
#define CP210X_PARTNUM_CP2102N_QFN24	0x21
#define CP210X_PARTNUM_CP2102N_QFN20	0x22
#define CP210X_PARTNUM_UNKNOWN	0xFF

/* CP210X_GET_COMM_STATUS returns these 0x13 bytes */
#define CP210X_COMM_STATUS_SIZE 0x13
struct cp210x_comm_status {
   __le32   ulErrors;
   __le32   ulHoldReasons;
   __le32   ulAmountInInQueue;
   __le32   ulAmountInOutQueue;
   u8       bEofReceived;
   u8       bWaitForImmediate;
   u8       bReserved;
} __packed;

/*
 * cp210x_get_config
 * Reads from the CP210x configuration registers
 * 'size' is specified in bytes.
 * 'data' is a pointer to a pre-allocated array of integers large
 * enough to hold 'size' bytes (with 4 bytes to each integer)
 */
static int cp210x_get_config(struct usb_serial_port *port, u8 requestType, u8 req, int val,
    unsigned int *data, unsigned int bufsize)
{
    struct usb_serial *serial = port->serial;
    struct cp210x_port_private *port_priv = usb_get_serial_port_data(port);
    __le32 *dmabuf;
    int result, i, length;

    /* Number of integers required to contain the array */
    length = (((bufsize - 1) | 3) + 1) / 4;

    dmabuf = kcalloc(length, sizeof(__le32), GFP_KERNEL);
    if (!dmabuf) {
        dev_err(&port->dev, "%s: out of memory\n", __func__);
        return -ENOMEM;
    }

    /* Issue the request, attempting to read 'bufsize' bytes */
    result = usb_control_msg(serial->dev, usb_rcvctrlpipe(serial->dev, 0),
        req, requestType, val,
        port_priv->bInterfaceNumber, dmabuf, bufsize,
        USB_CTRL_GET_TIMEOUT);

    /* Convert data into an array of integers */
    for (i = 0; i < length; i++) {
        data[i] = le32_to_cpu(dmabuf[i]);
    }
    kfree(dmabuf);
    if (result != bufsize) {
        dev_dbg(&port->dev, "%s: Unable to send config request, request=0x%x size=%d result=%d\n", __func__,
            req, bufsize, result);
        if (result > 0) {
            result = -EPROTO;
        }
        return result;
    }
    return 0;
}

/*
 * cp210x_set_config
 * Writes to the CP210x configuration registers
 * Values less than 16 bits wide are sent directly
 * 'bufsize' is specified in bytes.
 */
static int cp210x_set_config(struct usb_serial_port *port, u8 requestType, u8 req, int val, unsigned int *data, unsigned int bufsize)
{
    struct usb_serial *serial = port->serial;
    struct cp210x_port_private *port_priv = usb_get_serial_port_data(port);
    __le32 *dmabuf = NULL;
    int result;
    unsigned int i, length = 0;

    if (bufsize) {
        /* Number of integers required to contain the array */
        length = (((bufsize - 1) | 3) + 1) / 4;

        dmabuf = kmalloc(length * sizeof(__le32), GFP_KERNEL);
        if (!dmabuf) {
            dev_err(&port->dev, "%s: out of memory\n", __func__);
            return -ENOMEM;
        }

        /* Array of integers into bytes */
        for (i = 0; i < length; i++) {
            dmabuf[i] = cpu_to_le32(data[i]);
        }
    }

    result = usb_control_msg(serial->dev, usb_sndctrlpipe(serial->dev, 0),
        req, requestType, val,
        port_priv->bInterfaceNumber, dmabuf, bufsize,
        USB_CTRL_SET_TIMEOUT);

    if (dmabuf) {
        kfree(dmabuf);
    }

    if ((bufsize && (result != bufsize)) || (result < 0)) {
        dev_dbg(&port->dev, "%s: Unable to send request, request=0x%x size=%d result=%d\n", __func__,
            req, bufsize, result);
        if (result >= 0) {
            result = -EIO;
        }

        return result;
    }

    return 0;
}

/*
 * cp210x_quantise_baudrate
 * Quantises the baud rate as per AN205 Table 1
 */
static unsigned int cp210x_quantise_baudrate(unsigned int baud)
{
    if (baud <= 300) {
        baud = 300;
    } else if (baud <= 600) {
        baud = 600;
    } else if (baud <= 1200) {
        baud = 1200;
    } else if (baud <= 1800) {
        baud = 1800;
    } else if (baud <= 2400) {
        baud = 2400;
    } else if (baud <= 4000) {
        baud = 4000;
    } else if (baud <= 4803) {
        baud = 4800;
    } else if (baud <= 7207) {
        baud = 7200;
    } else if (baud <= 9612) {
        baud = 9600;
    } else if (baud <= 14428) {
        baud = 14400;
    } else if (baud <= 16062) {
        baud = 16000;
    } else if (baud <= 19250) {
        baud = 19200;
    } else if (baud <= 28912) {
        baud = 28800;
    } else if (baud <= 38601) {
        baud = 38400;
    } else if (baud <= 51558) {
        baud = 51200;
    } else if (baud <= 56280) {
        baud = 56000;
    } else if (baud <= 58053) {
        baud = 57600;
    } else if (baud <= 64111) {
        baud = 64000;
    } else if (baud <= 77608) {
        baud = 76800;
    } else if (baud <= 117028) {
        baud = 115200;
    } else if (baud <= 129347) {
        baud = 128000;
    } else if (baud <= 156868) {
        baud = 153600;
    } else if (baud <= 237832) {
        baud = 230400;
    } else if (baud <= 254234) {
        baud = 250000;
    } else if (baud <= 273066) {
        baud = 256000;
    } else if (baud <= 491520) {
        baud = 460800;
    } else if (baud <= 567138) {
        baud = 500000;
    } else if (baud <= 670254) {
        baud = 576000;
    } else if (baud < 1000000) {
        baud = 921600;
    } else if (baud > 2000000) {
        baud = 2000000;
    }
    return baud;
}

static int get_lsr_info(struct usb_serial_port *port,
    struct serial_struct __user *retinfo) {
    struct cp210x_port_private *priv = usb_get_serial_port_data(port);
    unsigned int result = 0;

    if (!retinfo) {
        return -EFAULT;
    }

    if (priv->transmit_empty) {
        result = TIOCSER_TEMT;
    }

    if (copy_to_user(retinfo, &result, sizeof (unsigned int))) {
        return -EFAULT;
    }
    return 0;
}

static int cp210x_ioctl(struct tty_struct *tty, unsigned int cmd,
    unsigned long arg) {
    struct usb_serial_port *port = tty->driver_data;
    struct cp210x_port_private *port_priv = usb_get_serial_port_data(port);
    int result = 0;
    unsigned long latch_buf = 0;

    switch (cmd) {
        case IOCTL_GPIOGET:
            if ((port_priv->bPartNumber == CP210X_PARTNUM_CP2103) ||
                (port_priv->bPartNumber == CP210X_PARTNUM_CP2104)) {
                result = cp210x_get_config(port,
                    REQTYPE_DEVICE_TO_HOST,
                    CP210X_VENDOR_SPECIFIC,
                    CP210X_READ_LATCH,
                    (unsigned int*)&latch_buf, 1);
                if (result != 0) {
                    return result;
                }
                if (copy_to_user((unsigned int*)arg, &latch_buf, 1)) {
                    return -EFAULT;
                }
                return 0;
            } else if (port_priv->bPartNumber == CP210X_PARTNUM_CP2105) {
                result = cp210x_get_config(port, REQTYPE_INTERFACE_TO_HOST,
                    CP210X_VENDOR_SPECIFIC, CP210X_READ_LATCH,
                    (unsigned int *)&latch_buf, 1);
                if (result != 0) {
                    return result;
                }
                if (copy_to_user((unsigned int*)arg, &latch_buf, 1)) {
                    return -EFAULT;
                }
                return 0;
            } else if (port_priv->bPartNumber == CP210X_PARTNUM_CP2108) {
                result = cp210x_get_config(port, REQTYPE_DEVICE_TO_HOST,
                    CP210X_VENDOR_SPECIFIC, CP210X_READ_LATCH,
                    (unsigned int *)&latch_buf, 2);
                if (result != 0) {
                    return result;
                }
                if (copy_to_user((unsigned int *)arg, &latch_buf, 2)) {
                    return -EFAULT;
                }
                return 0;
            } else {
                return -ENOTSUPP;
            }
            break;

        case IOCTL_GPIOSET:
            if ((port_priv->bPartNumber == CP210X_PARTNUM_CP2103) ||
                (port_priv->bPartNumber == CP210X_PARTNUM_CP2104)) {
                if (copy_from_user(&latch_buf, (unsigned int*)arg, 2)) {
                    return -EFAULT;
                }
                result = usb_control_msg(port->serial->dev,
                    usb_sndctrlpipe(port->serial->dev, 0),
                    CP210X_VENDOR_SPECIFIC, REQTYPE_HOST_TO_DEVICE,
                    CP210X_WRITE_LATCH, latch_buf, NULL, 0,
                    USB_CTRL_SET_TIMEOUT);
                if (result != 0) {
                    return result;
                }
                return 0;
            } else if (port_priv->bPartNumber == CP210X_PARTNUM_CP2105) {
                if (copy_from_user(&latch_buf, (unsigned int *)arg, 2)) {
                    return -EFAULT;
                }
                return cp210x_set_config(port, REQTYPE_HOST_TO_INTERFACE,
                    CP210X_VENDOR_SPECIFIC, CP210X_WRITE_LATCH,
                    (unsigned int *)&latch_buf, 2);
            } else if (port_priv->bPartNumber == CP210X_PARTNUM_CP2108) {
                if (copy_from_user(&latch_buf, (unsigned int *)arg, 4)) {
                    return -EFAULT;
                }
                return cp210x_set_config(port, REQTYPE_HOST_TO_DEVICE,
                    CP210X_VENDOR_SPECIFIC, CP210X_WRITE_LATCH,
                    (unsigned int *)&latch_buf, 4);
            } else {
                return -ENOTSUPP;
            }
            break;

        case TIOCSERGETLSR:
            return get_lsr_info(port, (struct serial_struct __user *)arg);

        default:
            return -ENOIOCTLCMD;
    }
}

static int cp210x_open(struct tty_struct *tty, struct usb_serial_port *port)
{
    int result;

    result = cp210x_set_config(port, REQTYPE_HOST_TO_INTERFACE, CP210X_IFC_ENABLE, UART_ENABLE, NULL, 0);
    if (result) {
        dev_err(&port->dev, "%s - Unable to enable UART: %d\n", __func__, result);
        return result;
    }

    /* Configure the termios structure */
    cp210x_get_termios(tty, port);

    /* The baud rate must be initialised on cp2104 */
    if (tty) {
        cp210x_change_speed(tty, port, NULL);
    }

    result = cp210x_set_config(port, REQTYPE_HOST_TO_INTERFACE, CP210X_EMBED_EVENTS, CP210X_ESCAPE, NULL, 0);
    if (result) {
        dev_err(&port->dev, "%s: Unable to embed events in UART\n", __func__);
        return result;
    }

    return usb_serial_generic_open(tty, port);
}

static void cp210x_close(struct usb_serial_port *port)
{
    usb_serial_generic_close(port);

    cp210x_set_config(port, REQTYPE_HOST_TO_INTERFACE, CP210X_IFC_ENABLE, UART_DISABLE, NULL, 0);
}

/*
 * Read how many bytes are waiting in the TX queue.
 */
static int cp210x_get_tx_queue_byte_count(struct usb_serial_port *port,
    u32 *count)
{
    struct usb_serial *serial = port->serial;
    struct cp210x_port_private *port_priv = usb_get_serial_port_data(port);
    struct cp210x_comm_status *sts;
    int result;

    sts = kmalloc(sizeof(*sts), GFP_KERNEL);
    if (!sts) {
        return -ENOMEM;
    }

    result = usb_control_msg(serial->dev, usb_rcvctrlpipe(serial->dev, 0),
        CP210X_GET_COMM_STATUS, REQTYPE_INTERFACE_TO_HOST,
        0, port_priv->bInterfaceNumber, sts, sizeof(*sts),
        USB_CTRL_GET_TIMEOUT);
    if (result == sizeof(*sts)) {
        *count = le32_to_cpu(sts->ulAmountInOutQueue);
        result = 0;
    } else {
        dev_err(&port->dev, "%s: failed to get comm status: %d\n", __func__, result);
        if (result >= 0) {
            result = -EIO;
        }
    }

    kfree(sts);
    return result;
}

static bool cp210x_tx_empty(struct usb_serial_port *port)
{
    int err;
    u32 count;

    err = cp210x_get_tx_queue_byte_count(port, &count);
    if (err) {
        return true;
    }

    return !count;
}

/*
 * cp210x_get_termios
 * Reads the baud rate, data bits, parity, stop bits and flow control mode
 * from the device, corrects any unsupported values, and configures the
 * termios structure to reflect the state of the device
 */
static void cp210x_get_termios(struct tty_struct *tty,
    struct usb_serial_port *port)
{
    unsigned int baud;

    if (tty) {
        cp210x_get_termios_port(tty->driver_data,
            &tty->termios.c_cflag, &baud);
        tty_encode_baud_rate(tty, baud, baud);
    } else {
        tcflag_t cflag;
        cflag = 0;
        cp210x_get_termios_port(port, &cflag, &baud);
    }
}

/*
 * cp210x_get_termios_port
 * This is the heart of cp210x_get_termios which always uses a &usb_serial_port.
 */
static void cp210x_get_termios_port(struct usb_serial_port *port,
    tcflag_t *cflagp, unsigned int *baudp)
{
    struct device *dev = &port->dev;
    tcflag_t cflag;
    unsigned int modem_ctl[4];
    u32 baud;
    unsigned int bits;

    cp210x_get_config(port, REQTYPE_INTERFACE_TO_HOST, CP210X_GET_BAUDRATE, 0, &baud, 4);

    dev_dbg(dev, "%s - baud rate = %d\n", __func__, baud);
    *baudp = baud;

    cflag = *cflagp;

    cp210x_get_config(port, REQTYPE_INTERFACE_TO_HOST, CP210X_GET_LINE_CTL, 0, &bits, 2);
    cflag &= ~CSIZE;
    switch (bits & BITS_DATA_MASK) {
        case BITS_DATA_5:
            dev_dbg(dev, "%s - data bits = 5\n", __func__);
            cflag |= CS5;
            break;
        case BITS_DATA_6:
            dev_dbg(dev, "%s - data bits = 6\n", __func__);
            cflag |= CS6;
            break;
        case BITS_DATA_7:
            dev_dbg(dev, "%s - data bits = 7\n", __func__);
            cflag |= CS7;
            break;
        case BITS_DATA_8:
            dev_dbg(dev, "%s - data bits = 8\n", __func__);
            cflag |= CS8;
            break;
        case BITS_DATA_9: // fall through
        default:
            dev_dbg(dev, "%s: data bits = 0x%x (unsupported, using 8 instead)\n", __func__, bits & BITS_DATA_MASK);
            cflag |= CS8;
            bits &= ~BITS_DATA_MASK;
            bits |= BITS_DATA_8;
            cp210x_set_config(port, REQTYPE_HOST_TO_INTERFACE, CP210X_SET_LINE_CTL, bits, NULL, 0);
            break;
    }

    switch (bits & BITS_PARITY_MASK) {
        case BITS_PARITY_NONE:
            dev_dbg(dev, "%s - parity = NONE\n", __func__);
            cflag &= ~PARENB;
            break;
        case BITS_PARITY_ODD:
            dev_dbg(dev, "%s - parity = ODD\n", __func__);
            cflag |= (PARENB|PARODD);
            break;
        case BITS_PARITY_EVEN:
            dev_dbg(dev, "%s - parity = EVEN\n", __func__);
            cflag &= ~PARODD;
            cflag |= PARENB;
            break;
        case BITS_PARITY_MARK:
            dev_dbg(dev, "%s - parity = MARK\n", __func__);
            cflag |= (PARENB|PARODD|CMSPAR);
            break;
        case BITS_PARITY_SPACE:
            dev_dbg(dev, "%s - parity = SPACE\n", __func__);
            cflag &= ~PARODD;
            cflag |= (PARENB|CMSPAR);
            break;
        default:
            dev_dbg(dev, "%s: Unsupported parity mode 0x%x, disabling parity\n", __func__, bits & BITS_PARITY_MASK);
            cflag &= ~PARENB;
            bits &= ~BITS_PARITY_MASK;
            cp210x_set_config(port, REQTYPE_HOST_TO_INTERFACE, CP210X_SET_LINE_CTL, bits, NULL, 0);
            break;
    }

    cflag &= ~CSTOPB;
    switch (bits & BITS_STOP_MASK) {
        case BITS_STOP_1:
            dev_dbg(dev, "%s - stop bits = 1\n", __func__);
            break;
        case BITS_STOP_2:
            dev_dbg(dev, "%s - stop bits = 2\n", __func__);
            cflag |= CSTOPB;
            break;
        case BITS_STOP_1_5: // fall through
        default:
            dev_dbg(dev, "%s: Unsupported number of stop bits 0x%x, using 1\n", __func__, bits & BITS_STOP_MASK);
            bits &= ~BITS_STOP_MASK;
            cp210x_set_config(port, REQTYPE_HOST_TO_INTERFACE,
                CP210X_SET_LINE_CTL, bits, NULL, 0);
            break;
    }

    cp210x_get_config(port, REQTYPE_INTERFACE_TO_HOST,
        CP210X_GET_FLOW, 0, modem_ctl, 16);
    if (modem_ctl[0] & 0x0008) {
        dev_dbg(dev, "%s: flow control = CRTSCTS\n", __func__);
        cflag |= CRTSCTS;
    } else {
        dev_dbg(dev, "%s - flow control = NONE\n", __func__);
        cflag &= ~CRTSCTS;
    }

    *cflagp = cflag;
}

/*
 * CP2101 supports the following baud rates:
 *
 *    300, 600, 1200, 1800, 2400, 4800, 7200, 9600, 14400, 19200, 28800,
 *    38400, 56000, 57600, 115200, 128000, 230400, 460800, 921600
 *
 * CP2102 and CP2103 support the following additional rates:
 *
 *    4000, 16000, 51200, 64000, 76800, 153600, 250000, 256000, 500000,
 *    576000
 *
 * The device will map a requested rate to a supported one, but the result
 * of requests for rates greater than 1053257 is undefined (see AN205).
 *
 * CP2104, CP2105 and CP2110 support most rates up to 2M, 921k and 1M baud,
 * respectively, with an error less than 1%. The actual rates are determined
 * by
 *
 *    div = round(freq / (2 x prescale x request))
 *    actual = freq / (2 x prescale x div)
 *
 * For CP2104 and CP2105, freq is 48Mhz, and prescale is 4 for request <= 365bps
 * or 1 otherwise.
 * For CP2110, freq is 24Mhz, and prescale is 4 for request <= 300bps or 1
 * otherwise.
 */
static void cp210x_change_speed(struct tty_struct *tty,
    struct usb_serial_port *port, struct ktermios *old_termios)
{
    u32 baud;

    baud = tty->termios.c_ospeed;

    /*
     * This maps the requested rate to the actual rate, a valid rate on
     * cp2102 or cp2103, or to an arbitrary rate in [1M, max_speed].
     *
     * NOTE: B0 is not implemented.
     */
    baud = cp210x_quantise_baudrate(baud);

    dev_dbg(&port->dev, "%s - setting baud rate to %u\n", __func__, baud);
    if (cp210x_set_config(port, REQTYPE_HOST_TO_INTERFACE,
            CP210X_SET_BAUDRATE, 0, &baud, sizeof (baud))) {
        dev_warn(&port->dev, "failed to set baud rate to %u\n", baud);
        if (old_termios) {
            baud = old_termios->c_ospeed;
        } else {
            baud = 9600;
        }
    }

    tty_encode_baud_rate(tty, baud, baud);
}

static void cp210x_set_termios(struct tty_struct *tty,
    struct usb_serial_port *port, struct ktermios *old_termios)
{
    struct device *dev = &port->dev;
    unsigned int cflag, old_cflag;
    unsigned int bits;
    unsigned int modem_ctl[4];

    cflag = tty->termios.c_cflag;
    old_cflag = old_termios->c_cflag;

    if (tty->termios.c_ospeed != old_termios->c_ospeed) {
        cp210x_change_speed(tty, port, old_termios);
    }

    /* If the number of data bits is to be updated */
    if ((cflag & CSIZE) != (old_cflag & CSIZE)) {
        cp210x_get_config(port, REQTYPE_INTERFACE_TO_HOST,
            CP210X_GET_LINE_CTL, 0, &bits, 2);
        bits &= ~BITS_DATA_MASK;
        switch (cflag & CSIZE) {
            case CS5:
                bits |= BITS_DATA_5;
                dev_dbg(dev, "%s - data bits = 5\n", __func__);
                break;
            case CS6:
                bits |= BITS_DATA_6;
                dev_dbg(dev, "%s - data bits = 6\n", __func__);
                break;
            case CS7:
                bits |= BITS_DATA_7;
                dev_dbg(dev, "%s - data bits = 7\n", __func__);
                break;
            case CS8:
                bits |= BITS_DATA_8;
                dev_dbg(dev, "%s: data bits = 8\n", __func__);
                break;
            /* case CS9:
                  bits |= BITS_DATA_9;
                  dev_dbg(dev, "%s: data bits = 9\n", __func__);
                  break; */
            default:
                bits |= BITS_DATA_8;
                dev_dbg(dev, "%s: cp210x driver doesn't support the number of bits requested (0x%x), using 8 bit mode\n", __func__, cflag & CSIZE);
                break;
        }
        if (cp210x_set_config(port, REQTYPE_HOST_TO_INTERFACE,
                CP210X_SET_LINE_CTL, bits, NULL, 0)) {
            dev_dbg(dev, "%s: Number of data bits requested not supported by device\n", __func__);
        }
    }

    if ((cflag     & (PARENB|PARODD|CMSPAR)) !=
        (old_cflag & (PARENB|PARODD|CMSPAR))) {
        cp210x_get_config(port, REQTYPE_INTERFACE_TO_HOST, CP210X_GET_LINE_CTL, 0, &bits, 2);
        bits &= ~BITS_PARITY_MASK;
        if (cflag & PARENB) {
            if (cflag & CMSPAR) {
                if (cflag & PARODD) {
                    bits |= BITS_PARITY_MARK;
                    dev_dbg(dev, "%s - parity = MARK\n", __func__);
                } else {
                    bits |= BITS_PARITY_SPACE;
                    dev_dbg(dev, "%s - parity = SPACE\n", __func__);
                }
            } else if (cflag & PARODD) {
                bits |= BITS_PARITY_ODD;
                dev_dbg(dev, "%s - parity = ODD\n", __func__);
            } else {
                bits |= BITS_PARITY_EVEN;
                dev_dbg(dev, "%s - parity = EVEN\n", __func__);
            }
        }
        if (cp210x_set_config(port, REQTYPE_HOST_TO_INTERFACE,
                CP210X_SET_LINE_CTL, bits, NULL, 0)) {
            dev_dbg(dev, "%s: Parity mode not supported by device\n", __func__);
        }
    }

    if ((cflag & CSTOPB) != (old_cflag & CSTOPB)) {
        cp210x_get_config(port, REQTYPE_INTERFACE_TO_HOST,
            CP210X_GET_LINE_CTL, 0, &bits, 2);
        bits &= ~BITS_STOP_MASK;
        if (cflag & CSTOPB) {
            bits |= BITS_STOP_2;
            dev_dbg(dev, "%s - stop bits = 2\n", __func__);
        } else {
            bits |= BITS_STOP_1;
            dev_dbg(dev, "%s - stop bits = 1\n", __func__);
        }
        if (cp210x_set_config(port, REQTYPE_HOST_TO_INTERFACE,
                CP210X_SET_LINE_CTL, bits, NULL, 0)) {
            dev_dbg(dev, "%s: Number of stop bits requested not supported by device\n", __func__);
        }
    }

    if ((cflag & CRTSCTS) != (old_cflag & CRTSCTS)) {
        cp210x_get_config(port, REQTYPE_INTERFACE_TO_HOST,
            CP210X_GET_FLOW, 0, modem_ctl, 16);
        dev_dbg(dev, "%s: read modem controls = 0x%.4x 0x%.4x 0x%.4x 0x%.4x\n",
            __func__, modem_ctl[0], modem_ctl[1],
            modem_ctl[2], modem_ctl[3]);

        if (cflag & CRTSCTS) {
            modem_ctl[0] &= ~0x7B;
            modem_ctl[0] |= 0x09;
            modem_ctl[1] = 0x80;
            dev_dbg(dev, "%s - flow control = CRTSCTS\n", __func__);
        } else {
            modem_ctl[0] &= ~0x7B;
            modem_ctl[0] |= 0x01;
            modem_ctl[1] |= 0x40;
            dev_dbg(dev, "%s - flow control = NONE\n", __func__);
        }

        dev_dbg(dev, "%s: write modem controls = 0x%.4x 0x%.4x 0x%.4x 0x%.4x\n",
            __func__, modem_ctl[0], modem_ctl[1],
            modem_ctl[2], modem_ctl[3]);
        cp210x_set_config(port, REQTYPE_HOST_TO_INTERFACE,
            CP210X_SET_FLOW, 0, modem_ctl, 16);
    }

}

static int cp210x_tiocmset(struct tty_struct *tty,
    unsigned int set, unsigned int clear)
{
    struct usb_serial_port *port = tty->driver_data;
    return cp210x_tiocmset_port(port, set, clear);
}

static int cp210x_tiocmset_port(struct usb_serial_port *port,
    unsigned int set, unsigned int clear)
{
    u16 control = 0;

    if (set & TIOCM_RTS) {
        control |= CONTROL_RTS;
        control |= CONTROL_WRITE_RTS;
    }
    if (set & TIOCM_DTR) {
        control |= CONTROL_DTR;
        control |= CONTROL_WRITE_DTR;
    }
    if (clear & TIOCM_RTS) {
        control &= ~CONTROL_RTS;
        control |= CONTROL_WRITE_RTS;
    }
    if (clear & TIOCM_DTR) {
        control &= ~CONTROL_DTR;
        control |= CONTROL_WRITE_DTR;
    }

    dev_dbg(&port->dev, "%s - control = 0x%.4x\n", __func__, control);

    return cp210x_set_config(port, REQTYPE_HOST_TO_INTERFACE, CP210X_SET_MHS, control, NULL, 0);
}

static void cp210x_dtr_rts(struct usb_serial_port *p, int on)
{
    if (on) {
        cp210x_tiocmset_port(p, TIOCM_DTR | TIOCM_RTS, 0);
    } else {
        cp210x_tiocmset_port(p, 0, TIOCM_DTR | TIOCM_RTS);
    }
}

static int cp210x_tiocmget(struct tty_struct *tty)
{
    struct usb_serial_port *port = tty->driver_data;
    unsigned int control;
    int result;

    result = cp210x_get_config(port, REQTYPE_INTERFACE_TO_HOST, CP210X_GET_MDMSTS, 0, &control, 1);

    if (result) {
        return result;
    }

    result = ((control & CONTROL_DTR) ? TIOCM_DTR : 0)
        |((control & CONTROL_RTS) ? TIOCM_RTS : 0)
        |((control & CONTROL_CTS) ? TIOCM_CTS : 0)
        |((control & CONTROL_DSR) ? TIOCM_DSR : 0)
        |((control & CONTROL_RING)? TIOCM_RI  : 0)
        |((control & CONTROL_DCD) ? TIOCM_CD  : 0);

    dev_dbg(&port->dev, "%s - control = 0x%.2x\n", __func__, control);

    return result;
}

static void cp210x_break_ctl(struct tty_struct *tty, int break_state)
{
    struct usb_serial_port *port = tty->driver_data;
    u16 state;

    if (break_state == 0) {
        state = BREAK_OFF;
    } else {
        state = BREAK_ON;
    }
    dev_dbg(&port->dev, "%s - turning break %s\n", __func__,
        state == BREAK_OFF ? "off" : "on");
    cp210x_set_config(port, REQTYPE_HOST_TO_INTERFACE, CP210X_SET_BREAK, state, NULL, 0);
}

static int cp210x_startup(struct usb_serial *serial) {
    struct usb_host_interface *cur_altsetting;
    struct cp210x_port_private *port_priv;
    int i;
    unsigned int partNum;

    for (i = 0; i < serial->num_ports; i++) {
        port_priv = kzalloc(sizeof (*port_priv), GFP_KERNEL);
        if (!port_priv) {
            return -ENOMEM;
        }

        cur_altsetting = serial->interface->cur_altsetting;
        port_priv->bInterfaceNumber = cur_altsetting->desc.bInterfaceNumber;

        usb_set_serial_port_data(serial->port[i], port_priv);

        /* Get the 1-byte part number of the cp210x device */
        cp210x_get_config(serial->port[i],
            REQTYPE_DEVICE_TO_HOST, CP210X_VENDOR_SPECIFIC,
            CP210X_GET_PARTNUM, &partNum, 1);
        port_priv->bPartNumber = partNum & 0xFF;
    }

    return 0;
}

static void cp210x_release(struct usb_serial *serial) {
    struct cp210x_port_private *port_priv;
    int i;

    for (i = 0; i < serial->num_ports; i++) {
        port_priv = usb_get_serial_port_data(serial->port[i]);
        kfree(port_priv);
    }
}

static int cp210x_process_packet(struct usb_serial_port *port,
    struct cp210x_port_private *priv, u8 *packet, int len) {
    int i;
    char status, flag, *ch;

    if (len < 1) { // malformed packet
        return 0;
    }
    status = packet[0] & CP210X_STATUS_B0_MASK;
    if (status) {
        u8 diff_status = status;

        if (diff_status & CONTROL_CTS) {
            port->icount.cts++;
        }
        if (diff_status & CONTROL_DSR) {
            port->icount.dsr++;
        }
        if (diff_status & CONTROL_RING) {
            port->icount.rng++;
        }
        priv->prev_status = status;
    }
    flag = TTY_NORMAL;
    if (packet[1] & CONTROL_CTS) {
        if (packet[1] & CONTROL_CTS) {
            flag = TTY_BREAK;
            port->icount.brk++;
            usb_serial_handle_break(port);
        } else if (packet[1] & 0x04) {
            flag = TTY_PARITY;
            port->icount.parity++;
        } else if (packet[1] & 0x08) {
            flag = TTY_FRAME;
            port->icount.frame++;
        }
        if (packet[1] & 0x02) {
            port->icount.overrun++;
            tty_insert_flip_char(&port->port, 0, TTY_OVERRUN);
        }
    }
    if (packet[1] & 0x40) {
        priv->transmit_empty = 1;
    } else {
        priv->transmit_empty = 0;
    }
    len--;
    if (!len) {
        return 0;    /* status only */
    }
    port->icount.rx += len;
    ch = packet;
    if (port->port.console && port->sysrq) {
        for (i = 0; i <= len; i++, ch++) {
            if (!usb_serial_handle_sysrq_char(port, *ch)) {
                tty_insert_flip_char(&port->port, *ch, flag);
            }
        }
    } else {
        tty_insert_flip_string_fixed_flag(&port->port, ch, flag, len);
    }
    return len;
}

static void cp210x_process_read_urb(struct urb *urb) {
    struct usb_serial_port *port = urb->context;
    struct cp210x_port_private *priv = usb_get_serial_port_data(port);
    u8 *data = (u8 *)urb->transfer_buffer;
    int i, len, count = 0;

    /* Detection of DCD Change */
    if (data[0] == CP210X_ESCAPE) {
        if (data[2] & CP210X_DCD_CHANGE_BIT) {    
            struct tty_struct *tty;

            port->icount.dcd++;
            tty = tty_port_tty_get(&port->port);
            if (tty) {
                usb_serial_handle_dcd_change(port, tty,
                    data[2] & CP210X_DCD_CHANGE_BIT);
            }
            tty_kref_put(tty);
        }
        wake_up_interruptible(&port->port.delta_msr_wait);
    }
    len = 256;
    for (i = 6; i < urb->actual_length; i += 256) {
        count += cp210x_process_packet(port, priv, &data[i], len);
    }
    if (count) {
        tty_flip_buffer_push(&port->port);
    }
}

module_usb_serial_driver(serial_drivers, id_table);

MODULE_DESCRIPTION(DRIVER_DESC);
MODULE_LICENSE("GPL v2");
